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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

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General Description. Lucia Glacier, which is between fifteen and twenty miles long and about two miles wide, is a valley glacier expanding in a piedmont bulb outside the mountain front, and in its lower portion covered with a broad waste of ablation moraine. Its sources are unknown, but in the main, if not entirely, are on the slopes of Mount Cook. That there is no large tributary heading farther back in the St. Elias Range is indicated by the morainic debris, which includes none of the crystalline rock of which these more remote mountains are composed. While the exact sources are unknown, it is certain that the glacier receives many tributaries, and some good-sized ones from both sides are visible from the lower portion of the glacier.
Opposite Floral Pass, where the Lucia Glacier is enclosed on both sides by mountain valley walls, the width of the glacier is 2 or 3 miles, but it expands beyond this point because the valley becomes wider and further down because the valley wall on the eastern side terminates. The width of the expanded piedmont bulb is 4 or 5 miles at the broadest part, the glacier being prevented from further expansion by the presence of the Floral Hills on the west and by the competing piedmont bulb of Atrevida Glacier on the east. The outer portion of the Lucia extends southward to the Kwik valley, forming one wall of that valley, while the Malaspina border, a mile or two away, forms the opposite wall. The Lucia and Atrevida piedmont bulbs coalesce and form a small piedmont glacier, similar to the great Malaspina, but supplied with ice from only two tributaries (Map 2, in pocket).
Basis for Study. This glacier, as well as the Atrevida, was crossed by Professor Russell and named by him in 1890.1 He first used this name, however, for Seward Glacier.8
It was next visited by the Geological Survey expedition of 1905, during which its lower portion was examined from a neighboring mountain and was crossed by the junior author and studied late in August. In the Geological Survey expedition of 1906 access to the glacier from the east was cut off by the advance and breaking of the Atrevida Glacier, but it was reached and crossed from the west by the senior author.8 The National Geographic Society's expedition of 1909 traveled to the eastern margin of the Lucia Glacier, but further exploration was checked by the advance of the glacier. We were, however, able to examine it from Ampitheatre Knob and from an elevation on Terrace Point, just above its eastern margin, from which we could see all parts of the glacier .except the upper portion far back in the mountains. The description of the 1909
 Nat. Geog. Mag., Vol. HI. 1891, pp. 02,106-108.
* Twelfth Ann. Kept, U. S. Geol. Survey, 1891, p. 60.
* For a description of this glacier in 1905 and 1906, from which portions of the following description are abstracted, see Tarr, R. 8., The Yakutat Bay Hegion, Alaska, Professional Paper 64, U. S. Geol. Survey, 1906, pp. 75-80.